I just pretended I was booking a trip from Henderson NV to OKC, and on
Step 5, it says the following (colors and bold per the web page):
Will Call Ticket Pick Up
ATTENTION: Valid Photo Identification Required for Will Call pick-up.
Pick up tickets at the following station no later than one hour prior to boarding:
QUICK CORNER MINI MART
450 N WATER ST
HENDERSON, NV
To pick up tickets, the credit card holder must present the credit card used for purchase, the reference number (displayed after purchase) and valid photo ID. If the credit card is not presented, a nonrefundable $15.00 fee will apply.
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So, there has to be some mechanism to match the credit card and passenger ID with the ticket.